package com.atguigu.gulimall.product.web;

import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;
import com.atguigu.gulimall.product.vo.Catelog2Vo;
import org.redisson.api.RCountDownLatch;
import org.redisson.api.RLock;
import org.redisson.api.RReadWriteLock;
import org.redisson.api.RSemaphore;
import org.redisson.api.RedissonClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ValueOperations;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.TimeUnit;

/**
 * @author: kaiyi
 * @create: 2020-08-29 13:30
 */
@Controller
public class IndexController {

  @Autowired
  CategoryService categoryService;

  @Autowired
  private RedissonClient redisson;

  @Autowired
  private StringRedisTemplate stringRedisTemplate;

  @GetMapping({"/","index.html"})
  public String indexPage(Model model){

    // 给Model里边写的数据默认会放到请求域中进行转发

    // 查出所有的1级分类
    List<CategoryEntity> categoryEntities = categoryService.getLevel1Categorys();

    model.addAttribute("categorys", categoryEntities);

    // 视图解析器进行拼串
    // classpath:/templates/ + 返回值+ .html
    return "index";
  }

  // index/catalog.json
  @ResponseBody
  @GetMapping("/index/catalog.json")
  public Map<String, List<Catelog2Vo>> getCatalogJson(){

    Map<String, List<Catelog2Vo>> map = categoryService.getCatalogJson();
    return map;
  }

  @ResponseBody
  @GetMapping(value = "/hello")
  public String hello() {

    //1、获取一把锁，只要锁的名字一样，就是同一把锁
    RLock myLock = redisson.getLock("my-lock");

    //2、加锁
    myLock.lock();      //阻塞式等待。默认加的锁都是30s
    //1）、锁的自动续期，如果业务超长，运行期间自动锁上新的30s。不用担心业务时间长，锁自动过期被删掉
    //2）、加锁的业务只要运行完成，就不会给当前锁续期，即使不手动解锁，锁默认会在30s内自动过期，不会产生死锁问题
    // myLock.lock(10,TimeUnit.SECONDS);   //10秒钟自动解锁,自动解锁时间一定要大于业务执行时间
    //问题：在锁时间到了以后，不会自动续期
    //1、如果我们传递了锁的超时时间，就发送给redis执行脚本，进行占锁，默认超时就是 我们制定的时间
    //2、如果我们指定锁的超时时间，就使用 lockWatchdogTimeout = 30 * 1000 【看门狗默认时间】
    //只要占锁成功，就会启动一个定时任务【重新给锁设置过期时间，新的过期时间就是看门狗的默认时间】,每隔10秒都会自动的再次续期，续成30秒
    // internalLockLeaseTime 【看门狗时间】 / 3， 10s
    try {
      System.out.println("加锁成功，执行业务..." + Thread.currentThread().getId());
      try { TimeUnit.SECONDS.sleep(20); } catch (InterruptedException e) { e.printStackTrace(); }
    } catch (Exception ex) {
      ex.printStackTrace();
    } finally {
      //3、解锁  假设解锁代码没有运行，Redisson会不会出现死锁
      System.out.println("释放锁..." + Thread.currentThread().getId());
      myLock.unlock();
    }

    return "hello";
  }

  /**
   * 保证一定能读到最新数据，修改期间，写锁是一个排它锁（互斥锁、独享锁），读锁是一个共享锁
   * 写锁没释放读锁必须等待
   * 读 + 读 ：相当于无锁，并发读，只会在Redis中记录好，所有当前的读锁。他们都会同时加锁成功
   * 写 + 读 ：必须等待写锁释放
   * 写 + 写 ：阻塞方式
   * 读 + 写 ：有读锁。写也需要等待
   * 只要有读或者写的存都必须等待
   * @return
   */
  @GetMapping(value = "/write")
  @ResponseBody
  public String writeValue() {
    String s = "";
    RReadWriteLock readWriteLock = redisson.getReadWriteLock("rw-lock");
    RLock rLock = readWriteLock.writeLock();
    try {
      //1、改数据加写锁，读数据加读锁
      rLock.lock();
      s = UUID.randomUUID().toString();
      ValueOperations<String, String> ops = stringRedisTemplate.opsForValue();
      ops.set("writeValue",s);
      TimeUnit.SECONDS.sleep(10);
    } catch (InterruptedException e) {
      e.printStackTrace();
    } finally {
      rLock.unlock();
    }

    return s;
  }

  @GetMapping(value = "/read")
  @ResponseBody
  public String readValue() {
    String s = "";
    RReadWriteLock readWriteLock = redisson.getReadWriteLock("rw-lock");
    //加读锁
    RLock rLock = readWriteLock.readLock();
    try {
      rLock.lock();
      ValueOperations<String, String> ops = stringRedisTemplate.opsForValue();
      s = ops.get("writeValue");
      try { TimeUnit.SECONDS.sleep(10); } catch (InterruptedException e) { e.printStackTrace(); }
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      rLock.unlock();
    }

    return s;
  }


  /**
   * 车库停车
   * 3车位
   * 信号量也可以做分布式限流
   */
  @GetMapping(value = "/park")
  @ResponseBody
  public String park() throws InterruptedException {

    RSemaphore park = redisson.getSemaphore("park");
    park.acquire();     //获取一个信号、获取一个值,占一个车位
    boolean flag = park.tryAcquire();

    if (flag) {
      //执行业务
    } else {
      return "error";
    }

    return "ok=>" + flag;
  }

  @GetMapping(value = "/go")
  @ResponseBody
  public String go() {
    RSemaphore park = redisson.getSemaphore("park");
    park.release();     //释放一个车位
    return "ok";
  }


  /**
   * 放假、锁门
   * 1班没人了
   * 5个班，全部走完，我们才可以锁大门
   * 分布式闭锁
   */

  @GetMapping(value = "/lockDoor")
  @ResponseBody
  public String lockDoor() throws InterruptedException {

    RCountDownLatch door = redisson.getCountDownLatch("door");
    door.trySetCount(5);
    door.await();       //等待闭锁完成

    return "放假了...";
  }

  @GetMapping(value = "/gogogo/{id}")
  @ResponseBody
  public String gogogo(@PathVariable("id") Long id) {
    RCountDownLatch door = redisson.getCountDownLatch("door");
    door.countDown();       //计数-1

    return id + "班的人都走了...";
  }

}
